The present invention is related to generators, and in particular to a rotating resistor pack employed in a generator.
A typical generator assembly includes a rotor portion and a stator portion. Mechanical energy is provided to the generator via a shaft connected to the rotor portion that is converted into electrical energy that is provided via the stator portion.
Many generators take advantage of three stages, including a permanent magnet stage, an exciter stage and a main stage. The exciter stage includes an exciter stator winding for receiving DC power that energizes the exciter stator and generates the desired magnetic field. Rotational energy provided by the shaft causes the exciter rotor to move through the magnetic field, resulting in the generation of alternating current (AC) electric power in the exciter rotor. A rotating rectifier assembly is mounted within the rotor for converting the AC power to a direct current (DC) electric power that is supplied to the main rotor winding. The DC power provided to the rotating main rotor winding results in a rotating magnetic field that generates AC power in the stator windings.
Suppression resistors may also be included within or nearby the rotating rectifier assembly to provide an alternate path for voltage and current transients and protect the rotating rectifier assembly. However, the rotating rectifier assembly and the suppression resistors are mounted on the rotating shaft, and are therefore subject to the centrifugal forces associated with the rotating shaft.